Manual unshift mechanism



Dec, 21, 1948. w. M. ONEIL 2,456,729

- MANUAL UNSHIFT MECHANISM Filed Oct. 16, 1947 v INVENTOR WILLIAM M; oNEIL ATTORNEY Patented Dec. 21, 1948 UNITED STATES PATENT OFFICE WilliamM. ONeilQOak Park, 111., assignor to Teletype Corporation, Chicago,111., a corporation of Delaware Application October 16, 1947, Serial No.780,222

5 Claims. 1

This invention relates to printing telegraph apparatus and moreparticularly to attachments for receiving telegraph printers.

It has been found frequently that printing telegraph reception,particularly in the case of radio printing telegraphy, is not alwaysreliable. many cases this poor reception is not the fault of thereceiving equipment but rather is due to the inability of thetransmitting station to beam the transmissions toward the receiver. Whenthe receiver is aboard ship the inability to use diversity receptionalso results in many errors in the received copy, and in time of warreception is sometimes poor due to the attempt by the enemy to jam theair. One of the more frequent errors resulting from these causes is theshifting of the receiver platen to the shift position during a periodwhen the transmitting station is sending lower case signals. When thisoccurs it is necessary to manually force the platen into lower caseposition in order that the message will be intelligible.

Accordingly, the primary object of this invention is to provide anattachment for receiving telegraph printers whereby the platen may beautomatically unshifted whenever a special key is depressed.

Another object of this invention isto prevent the unshifting of theplaten at a time when a shift signal is received. i.

A further object of this invention is to prevent the selection of theshift function at a time when the special unshifting key is held in adepressed position.

Other objects and advantages of the invention will be apparent and theinvention will be more readily understood from the following descriptionwhen read in conjunction with the accompanying drawing.

A complete description of the printer used to .1

illustrate this invention is given in U. SbPatent No. 1,904,164 toMorton et al., and therefore all elements of the printer which are notnecessary for an understanding of this invention have been omitted inthe present drawing for the sake of A vertical shift link 14 is fastenedpivotally- Atongued end IQ of the bell crank i1 is operably connected toa shift lever 2! which is mounted pivotally by a bolt 22 on a shiftlever support 23. An unshift intermediate lever or push bar 24 isconnected operably with the shift lever 21 by a bolt 25 and is urgeddownwardly and rearwardly by a spring 23. Similarly, a shiftintermediate lever or push bar 21 is connected operably to the shiftlever 2| by a bolt 28 and is similarly urged downwardly and rearwardlyby a spring 29.

.A series of vanes 3i, pivotally supported in the main frame of theprinter, are adapted to be position'ed in a permutation corresponding tothe sig nal received by the printer. An unshift code bar or functionlever 32 and a shift code bar or function lever 33 are supportedpivotally on a function lever shaft 34 and are urged towards the vanes3| by function lever springs 35 and 36 respectively. The unshiftfunction lever 32 is provided with a horizontal arm 3'! which cooperateswith and raises the unshift push bar 24 when the unshift function hasbeen selected. A similar horizontal arm 38 on the shift function leverraises the shift push bar 21 when the shift function has been selected.

A function bail M is mounted pivotally on a shaft 42 and is continuouslyurged in a clockwise .direction about the shaft 42 by a function boilspring 43, whereby a function bail cam follower i4 is continuously heldon a function bail cam 45 mounted on a rotary shaft 46 which for thepurposeof this invention may be considered as the shaft 16 shown in Fig.'7 of the aforementioned U. S. Patent No. 1,904,164, issued to Morton etal. A function lever bail roller 4! secured to a printing bail (notshown) and movable therewith normally engages the rear vertical arms ofthe function levers 32 and 33 to hold the function levers 32 and 33 awayfrom the vanes 3!. As a printing bail cam follower (not shown) rides upthe high portion of a printing bail cam (also not shown) the functionlever bail roller M drops allowing the function lever corresponding tothe selected permutation of vane positions, to pivot about the shaft 34and thereby raise the corresponding push bar. At this time the functionbail H pivots counterclockwise around the shaft 42 and a function bailblade 48 moves rearwardly engaging a latch or shoulder 39 on theselected function push bar to move this push bar rearwardly to performthe selected function.

Mounted pivotally in the printer base on a shaft 5! is a key lever 52having a special key .53 thereon. The key lever '52, when depressed,cooperates with and pivots a bell crank lever 54 on a shaft 55. The bellcrank lever 54 is provided with an unshift push bar lifter 56 which isadapted to engage an extension 57 on the unshift push bar 2i when thekey 53 is depressed to thereby raise the unshift push bar 24 so that thelatch 45 thereon will be engaged by the function bailhladesfi duringthenextrearward movement-of the frinctioir bail 3bladei48. Thebell cranklever 55 is also provided with a. blocking 4 gaging said unshiftingmeans to cause the unshifting of said platen, and means on said 1everfor engaging said shifting means when a shift signal has been receivedto block the further 5 movement of said lever and thereby prevent theunshifting of said platen when a shift signal has .beenmeceired. i V

".3;"rIn :a receiving telegraph printer, a shiftable platem'means forshifting the platen including a portion '58 which is adapted to move infronteofnlfl shift function lever and shift push bar, means for theshift function lever 33 when the key 535is depressed. If, however, theshiftziurictioihhas been selected on the vanes..3i.. at ,thetimejthe key53 is depressed theishiftlfiurictiortleueffil now being free to do so,will have pivoted'forward to a position where it blocks the movement ofblocking portion 58 which preven ts' therunshift push bar lifter 55 fromraisingtheunshift push bar 24 and thusnprevents the simultaneousengagement of the, shift andunshift push bars with thefunction bail:blade 48.;"If'=-the--keyt53 is .depressed before a'shiftisi nal' has -been--received but isncontinuou sly held} depressed :untila shift signalis received 'theiblocking portiorf'fia -is'-in front of theshiftfunction leveri33'"whlchiprevents'the selectionofjtheshiftfunctioii lever and .jalso prevents the simultaneous engageme'ntof theshift and unshift push bars. "This-Will cause-the printer totype inlower case during a period'when .it should be typing inppper case;butthe number of upper case signals received ;is, ordinarily-very smallrelative to the numberhfdowercasesigfials received. so therefore the,number of errors 'inthe copy due .t0;this, gcausei'will he verysm'all.

(When theflplaten' i3:is'"in shift-position: at a time when it shojuldbein yu-nshift: position the isdepression. of. the, special key" 53results -ini'ithe actuation of push, bar24:"duringthemext rearward.movement of thei functionbailt bladeilil, through mechanism"hereinbefore zdescribed, which; pivots the shift lever '2 Iclockwiseywhich in turn pivots the belhcrank,"Hi-counterclock- Wiseto'thereby. raisdthe'verticahtshiftj-link M, which causes theplaten'frame I l to pivot at l2 and thereb move the platen. downwardlyto'unshift position.

By; this invention there is provided a' veryie'fii- ."cient :andeconomical;'attachment'for facilitating the manual unshifting 'of the.."platen of, a receiving 'telegraplrprinter, "It is1contempl'ated and,is withinthe realm of this,'in'ventionr-whemthe copy is primarilyuppergcase signals,.ithatrthe shift function push bar; will. beaoperableby'jthe speciaLkeyon the printer base.

Obviouslyiother changes and modificationsmay be. made in theinvention'without departingffrom the spiritthereof.

What is'claim'ed is:

1 1. ,In a telegraph printer, a plurality jof functior performing means,each, ofsaid function per forming means being responsive normally, to a7 signal corresponding thereto to, cause .,a.; corresponding function1301b? performed, a special key, a leverrop rab e whensaid specialkeyisd messed for normally enga ing .oneiofwsaid functionperformin meansto causepitto perform itsspecified function, and means on saidlever forengaging a second function performing. means when a s gnal correspondingto said function performingmeans has been received to prevent saidleverfromengaging said first function-performing means.

2.--Inareceiving*telegraph'printer: having a v shittable platen, meansforshifting-said platen, m-eans:for unshiftingsaid-platen; adevenrespon-:sivel-to the depression of a-key for normallyem unshiifting the platenincluding an unshift push wears a ereciprocable function bail foractuating .said nushibars when in engagement therewith to5.;thfifigbyzcaus'ithe platen to be shifted or unshifted, aspeciahdepressible key mounted on a pivotal key lever, a bell cranklever adapted to be 'pivotedvvehen said key lever is depressed to nor-..mally, move the unshift push bar into engagement with said functionbail, and blocking means on said bell crank lever adapted to engage saidshift function If lever "when :the shift function "lever isactuatedin'responseto ashi'ft signalto move the shift push barintoengagement with the function bailywhereby s'aidbell crank -lever isprevented =f-rom: movingthe unshift pushbar'into engage- -ment'with thefunction bail; *sa'id blocking means ".on'said bell-crahkleve'r beingadapted to'normally Eblo-ck"the mrovement of the shift function lever"x'whemthe special key -is-'-depressed, Wherebythe -shift* function:lever isprev'en-ted from moving the "fsliiftpuslr ,bar'i'ntoengaerhentWith the function bail.

Mina telegraph prin-ter; a plurality "of-permutata-ble members adaptedto'be permutatably =positiened--in accordance'with" a signal received bythe-printer; a-plurality of selectable code bars =c ooperating-withsaid'permutatable members and adapted to be-moveddntoselected positionwhen a-"-oorresporrdi-ngpermutation-of sa-idpermutata- -40"*ble members"occurs; a" plurality of intermediate levers each-adapted to-be movedinto-operable position when a correspondingselectable code bar is-movedinto-selectedposition-means for operat- --ing-saidi-ntermediateleverswhen moved into'openable position; a manually operable lever" for Ymoving one- "of "s'aidintermediate levers into operable position, andmeans on said manually ;operableelevei for blocking from'selection oneof said Selectaible-cOdebars corresponding to a second intermediatelever to prevent "the simultaneous movement and operation of more thanone of said -intermediate levers.

53 Ina telegraph "printer; a plurality of permutatablemembers adapted tobe permutatably oo p-o'sitioned in accordance" with a signal received bythe printer; a plurality 'of-selectable code bars coo-peratingwith saidper-mutatable members and ==adapted-tobe moved into selected positionwhen a corresponding permutation of'said permutata- "v blernembersoccurs, a-plurality of intermediate.

.leverseachadapted "to -be-moved into operable '-"position:-'when acorresponding selectable code bar -issele'eted; means for operating saidintermediate deversdvhenmoved into operable position, a manr-ua-llyoperableeleverfor-normally moving one of said intermediate levers intooperable position, and- -means-on said manually operable lever forengaging a selected one of said plurality of se- '--lectab1e*cod bars toarrest the further operation 'of .-said:'mamial-ly operable lever andprevent the isimultaneousi movement and operation of more than'onebfsaid'intermediate levers.

"No references cited.

